Sure, and I use Tuta. Those are outliers, the vast majority use gmail, or at least the vast majority in my circles do.
It’s the same thing as the network effect, just a little less ubiquitous, people will tend to use whatever everyone else uses. Getting something new like email (SMTP) is a huge endeavor, it’s a lot easier to just build a centralized service and get people to use that, and most people will use the same provider anyway.
I don’t like it, but I understand why it works and is so common.
No, those being outliers means the email argument isn’t particularly strong, especially when talking about a new standard. If most people use a single service anyway, why would a company go out of its way to make something decentralized? And for something like encrypted chat, that’s a lot of extra work.
